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That is, however, what Uber, Side-car and their ilk get around. Calling themselves "car sharing" puts their drivers in the same rulebook as any motorist. If anyone with a license can qualify to "car share" it means that not only does one have a larger pool of "qualified drivers" to tap but it also provides an easy "opt in" for those whose need for money outstrips their concern for safety--- effectively lowering standards for "taxi drivers" to "has a valid drivers license" and maybe "no DUI conviction over the last year". The only government planning instrument available would be to increase liability requirements for all car sharing--- ultimately creating negative incentives for car pooling. Since the cost of entering a market is relatively low these "app driven" solutions have lower transaction and fixed costs and can "pick up and leave" should profits fail to meet their expectations leaving shards and a vacuum behind them...

Why is it impossible to have new regulations which apply to Uber (and its ilk)? That is, I don't see what makes it particularly difficult to differentiate between a car pool and a hire car. If they can be outlawed without outlawing car pooling, why can they not be regulated without outlawing car pooling?